This report summarizes findings of laboratory and construction evaluations of using residue from an atmospheric fluidized bed combustion (AFBC) process as a component in an experimental road base and subbase application. The base mixture contains pulverized fuel ash, AFBC residue, and limestone aggregates used as bulk filler.

Two 750-foot test sections of a 22-foot wide roadway, containing the experimental mixtures, were constructed in May and June 1988. Prior to construction, in-place California Bearing Ratio tests, moisture content determinations and Road Rater deflection tests were performed on the prepared subgrade.

During construction of the experimental base and subbase layers, relative compaction and moisture contents of the materials were monitored by nuclear devices. Specimens were compacted for subsequent evaluations. Initial post-construction evaluations included compressive strength development, elastic modulus, Road Rater deflection analyses, and monitoring expansion of the experimental mixtures both in the field and in the laboratory.
Source: University of Kentucky
Authors: David Q. Hunsucker | R. Clark Graves